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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Series expansions of fundamental solutions are essential to algorithms and analysis of the null field method (NFM) and to analysis of the method of fundamental solutions (MFS). For linear elastostatics, new Fourier series expansions of FS are derived, directly from integration. The new expansions of the FS are simpler than those in Chen et?al. (J Mech 26(3):393?C401, 2010), thus facile to application in NFM and MFS. The new series expansions of FS in this paper are important to both theory and computation of linear elastostatics. Some computation of the MFS for linear elastostatics is provided, where the expansions of fundamental solutions are a basis tool in analysis. Numerical results of a simple example are reported, accompanied with error analysis. 相似文献
992.
This paper analyzes the execution behavior of “No Random Accesses” (NRA) and determines the depths to which each sorted file is scanned in growing phase and shrinking phase of NRA respectively. The analysis shows that NRA needs to maintain a large quantity of candidate tuples in growing phase on massive data. Based on the analysis, this paper proposes a novel top-k algorithm Top-K with Early Pruning (TKEP) which performs early pruning in growing phase. General rule and mathematical analysis for early pruning are presented in this paper. The theoretical analysis shows that early pruning can prune most of the candidate tuples. Although TKEP is an approximate method to obtain the top-k result, the probability for correctness is extremely high. Extensive experiments show that TKEP has a significant advantage over NRA. 相似文献
993.
X.M. An L.X. Li G.W. Ma H.H. Zhang 《Computer Methods in Applied Mechanics and Engineering》2011,200(5-8):665-674
In the partition of unity (PU)-based methods, the global approximation is built by multiplying a partition of unity by local approximations. Within this framework, high-order approximations are achieved by directly adopting high-order polynomials as local approximations, and therefore nodes along sides or inside elements, which are usually adopted in the conventional finite element methods, are no more required. However, the PU-based approximation constructed in this way may suffer from rank deficiency due to the linear dependence of the global degrees of freedom. In this paper, the origin of the rank deficiency in the PU-based approximation space is first dissected at an element level, and then an approach to predict the rank deficiency for a mesh is proposed together with the principle of the increase of rank deficiency. Finally, examples are investigated to validate the present approach. The current work indicates such a fact that the rank deficiency is an unrelated issue to the nullity of the global matrix. It can be resolved in its own manner. 相似文献
994.
提出了一种查找化合物中立体中心的算法 ,通过该算法可以找到和确认化合物中由于不对称碳和碳碳双键等产生的所有的立体中心。 相似文献
995.
形状特征局部操作在实体造型中的实现 总被引:1,自引:0,他引:1
李茹 《计算机工程与应用》2000,36(2):75-77
文章介绍了实体造型中形状特征的局部操作,研究了包含形状特征描述的数据结构,分析了形状特征的分类、框架、特征间的联系及有关操作,分析了欧拉运算及实现思路,在此基础上对实体造型进行局部操作,提高了造型中的运算效率,也对特征造型作了相应的探讨。 相似文献
996.
997.
An Internet-based negotiation server for e-commerce 总被引:6,自引:0,他引:6
Stanley Y.W. Su Chunbo Huang Joachim Hammer Yihua Huang Haifei Li Liu Wang Youzhong Liu Charnyote Pluempitiwiriyawej Minsoo Lee Herman Lam 《The VLDB Journal The International Journal on Very Large Data Bases》2001,10(1):72-90
This paper describes the design and implementation of a replicable, Internet-based negotiation server for conducting bargaining-type
negotiations between enterprises involved in e-commerce and e-business. Enterprises can be buyers and sellers of products/services
or participants of a complex supply chain engaged in purchasing, planning, and scheduling. Multiple copies of our server can
be installed to complement the services of Web servers. Each enterprise can install or select a trusted negotiation server
to represent his/her interests. Web-based GUI tools are used during the build-time registration process to specify the requirements,
constraints, and rules that represent negotiation policies and strategies, preference scoring of different data conditions,
and aggregation methods for deriving a global cost-benefit score for the item(s) under negotiation. The registration information
is used by the negotiation servers to automatically conduct bargaining type negotiations on behalf of their clients. In this
paper, we present the architecture of our implementation as well as a framework for automated negotiations, and describe a
number of communication primitives which are used in the underlying negotiation protocol. A constraint satisfaction processor
(CSP) is used to evaluate a negotiation proposal or counterproposal against the registered requirements and constraints of
a client company. In case of a constraint violation, an event is posted to trigger the execution of negotiation strategic
rules, which either automatically relax the violated constraint, ask for human intervention, invoke an application, or perform
other remedial operations. An Event-Trigger-Rule (ETR) server is used to manage events, triggers, and rules. Negotiation strategic
rules can be added or modified at run-time. A cost-benefit analysis component is used to perform quantitative analysis of
alternatives. The use of negotiation servers to conduct automated negotiation has been demonstrated in the context of an integrated
supply chain scenario.
Received: 30 October 2000 / Accepted: 12 January 2001 Published online: 2 August 2001 相似文献
998.
This study presents a novel means of resolving multiple objective goal programming (GP) problems with quasi-convex linear penalty functions. The proposed method initially expresses a quasi-convex function by the maximum operator of two convex functions, then solves it via a linear programming technique. The proposed method does not contain any zero–one variables; nor does it require dividing the multi-objective quasi-convex GP problem into large sub-problems as in conventional methods. Some illustrative examples are provided. 相似文献
999.
改进遗传算法搜索性能的研究 总被引:1,自引:0,他引:1
本文针对改进遗传算法的搜索性能,提出了一种新的变异算子-自适应多位变异算子,它根据每一代的每一个体在当代中的优劣程度,自适应地控制其发生变异的位数。适应度差的个体变异的位数多,一方面使差的模式生存机会少,另一方面增加了种群的多样性,同时也扩大了搜索范围。我们用模式定理证明了该算子的有效性,并且我们作的仿真实验也同样表明该算子能大大改进遗传算法的搜索性能。 相似文献
1000.
一种采用80C196KC的伺服控制系统的设计 总被引:1,自引:0,他引:1
介绍了一块用于三轴稳定跟踪装置中位置伺服控制卡的软、硬件设计。硬件电路实现了数据采集、D/A输出、上下位机通讯和输入输出信号接口等功能。单片机程序采用C96语言编制。软硬结合进行系统联调 ,效果很好 相似文献